Art of obtaining serum from blood



Nov. 4 1924. 1,513,949

. W. B. WE5C OTT ART OF OBTAINING SERUM FROM BLOOD Filed Jam-19 1920 1. 21 I III ATTORNEYS Patented Nov. 4, 1924.

UNITED. STATES PATENT OFFICE.

WILLIAM BURTON WESCO'TT, WELLESLEY HILLS, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO AMERICAN PROTEIN CORPORATION, OF BOSTON, MASSA- CHUSETTS, A CORPORATION OF MASSACHUSETTS.

ART OF OBTAINING SERUM FROM BLOOD.

Application filed January 19, 1920. Serial No. 352,827.

To all whom it may concern:

Be it known that 1, WILLIAM -BURTON WESOOTT, a citizen of the United States, and resident of Wellesley Hills in the county of Norfolk and State of Massachusetts, have invented new and useful Improvements in the Art of Obtaining Serum from Blood, of which the following is a specification.

This invention relates to the art of obtainingv clear serum from blood. For human food or therapeutic purposes, it is ingeneral necessary that serum be substantially free from haemoglobin, the presence of which in the normally pale yellow serum results in a change of color from yellow through light brown to a (lee ruby. To obtain clear serum by the or inary methods heretofore practiced it has beennecessary to treat the serum chemically to remove coloring matter (haemoglobin) with which it becomes co-ntaminated and stained during the separation of the serum. The object of the present invention is to separate serum from blood in such a way as to prevent contamination of the serum by haemoglobin, to obtain from the blood the maximum possible amount of serum, and to devise a method capable of being practiced on a large and commercially profitable scale adaptable to slaughter-house conditions.

Blood, from one point of view, may be considered to be a fluid tissue. composed of a transparent pale yellow liquid (the blood plasma) in WhlCh a vast number of particles (the red and white corpuscles) are suspended. It is striking characteristic of blood that in ge eral outside of the organism it coagulates to a jelly-like mass in a few minutes, generally from five to ten minutes after the blood leaves the body. In the coagulation of the blood a chemical transformation takes place inthe plasma b which fibrinogen, one of the proteins, separates out as an insoluble, stringy, solid fibrin. The transformation of fibrinogen into fibrin is believed to require the presence of an enzymotic substance found in serum and in fibrin, and generally desi ated as fibrin ferment or thrombin. The ormation of fibrin ferment in nncoagulated blood is not; clearly understood, but it is common knowledge that coagulation is stimulated by the addition of fibrin or serum from previously coagulated blood. The coagulation or the forming of the fibrin produces a spongy network of tendrils enmeshing the red and white corpuscles and enclosing, sponge-like, the fluids of the blood. F ibrin is formed throughout the entire mass of the blood and tends, after its formation, to contract. The velocity of coagulation and the contractibility of the resulting fibrin may vary over a wlde range; thus blood protected from foreign bodies, such as the walls of the receiver, dust, etc., as by collecting it in parafiined vessels or under oil, will remain fluid for hours or even days, while on the other hand, the addition of serum 'or fibrin from previously coagulated blood will cause rapid coagulation and produce a fibrin clot of marked contractibility. On contracting, the fibrin clot expresses a liquid, the blood serum. Serum differs from' the blood plasma chiefly in the absence of fibrinogen, which has gone into the formation of fibrin. The serum expressed from the coagulum by the contraction of the fibrin clot with the methods heretofore used is generally more or less colored, due to the presence of haemoglobin, the red colorin matter of the blood, in red corpuscles whic have escaped from the fibrin tendrils, or haemoglobin which has been freed from the corpuscles by their mechanical rupture or otherwise. The red blood corpuscles in mammalia are round, biconcave discs and are composed of two principal constitutents, the stroma which forms the real protoplasm, and the intra-globular contents, which is chiefly haemoglobin. It is held in the literature that the stroma are a semi-permeable protoplasmic structure soaked with haemoglobin, from which the haemoglobin will be freed by mechanical rupture or by haemolysis, which latter occurs when the osmotic equilibrium is disturbed, as

by a solution of less concentration than the serum. For instance, upon the addition of water to the serum. and the consequent dilutionof the serum, the corpuscles swell, due to the taking up of water, and the haemoglobin asses from the ,stroma into the serum. arious chemical substances such as chloroform, and most. alkalis, have a strong haemolytic action. The corpuscle is so delicatea structure that haemolysis is produced mechanically byrapid stirring and also by thawing after freezing.

- The coloring matter, while in. the corpuscles, may be removed from the serum by a centrifuge or by merely allowing the corpuscles to settle out; But such coloring matter as may have been freed from the corpuscles is very difficult to remove without serious chemical modification of the .serum itself. Known methods heretofore racticed of obtaining serum from blood may e divided into two groups. The first, which is the more generally practiced, consists in allowing the blood to clot in a large shallow vessel, cutting .the clot into small cubes by means of a coarse meshed wire net, and spreading the cubes upon a fine wire net to drain; The second method consists in defibrinating .the blood and removin the corpuscles either by passing the lood i .through a centrifuge or allowing it to stand and the corpusclesto settle out. 7

By the first method, the serum yielded by the contraction of the fibrin in the small cubes is highly colored, both by red corpuscles and by free haemoglobin resulting from the mechanical rupture of the corpuscles during the severance of the clot. As the flow continues, serum from the inside of the cubes washes-out the corpuscles which are not enmeshed, and also the haemoglobin of the ruptured corpuscles, so that the last of the yield is more nearly clear'than the first. But the percentage yield of serum even approximately free of haemoglobin is very small. Furthermore, the long exposure to the air at 'room temperature low temperatures materially reduce contractibili'ty) results in the rapid growth of bacteria which unfits the product for human consum tion.

T e second method gives a higher yield of 'serum free from blood corpuscles, but still too highly colored by free haemoglobin from corpuscles broken by the stirring by which defibrination was effected to be desirableja's a-food roduct. Of-the chemical steps capable of removing. the haemo lobin, some disadvantafgeously modify t e character and properties serum proteins, and of those which do ot modify- 1-, e protein properties, some are o .co'stly to be of commercial interest and -"r"' -others cannot -be used with safety to producefa product. destined for. human .con-

sumption.

' In, producing 'serum free' of haemoglobin by expression-from a contracting clot, it is necessarythatthe'clotbe .uncut and unrup- ....tur ed,1 and, also that the blood becaught and --the "-;clot.="'formed inx'a vessel,[.s.the.- walls of whit:

.f r .be 'P entenc s-t;

This is important for two reasons: First, were the fibrin to adhere, it would, upon the contraction of the clot, tear away from the walls, and in so doing liberate many red corpuscles, and also, which is more serious, rupture many others, thereby permitting free haemoglobin to escape into the serum. Secondly, the contraction of a clot free to contract is greater than that of a clot which has lost much of its-contractibility in its efforts to tear itself free from the walls of the container. Consequently a greater yield is obtained when the'clot is quite free to contract. As above pointed out, it is important that the walls of the container in which the clot is formed be greased or paraflined to prevent adhesion of the clot. But this unctuousness tends to seriously increase coagulation time and decrease the contractibility of the clot. The present invention provides, as one of its steps, a method of so accelerating coagulation as to produce a dense clot, notwithstanding the fact that the container walls are greased. v This step consists in introducing, in a commercially practic'able. manner, a powerful, sterile, fibrin ferment, and is preferably accomplished by allowing shreds of fibrin from the previous dot to remain adherent to the core about which the clot forms. These fibrin shreds may be sterilized and dried without appreciable reduction of their enzymotic properties. It is obvious that the same end may be achieved by other means, such as the. addition of serum to the blood, but becauseof the difiiculties of sterilization of serum, we prefer to use fibrin. 1

It isalso important, if clear serum is to be obtained, that the clot be formed in a vessel, the unctuous walls of which are perfectly dry, as the presence of water would produce haamolysis and a consequent colorin of the serum by free haemoglobin.

in order to obtain the maximum yield of serum, it is also necessary that the clot be of such dimensions that the average distance which the serum has to travel through theclot to the surface is small. I have found that the limit of distance forobtaining substantially the maximum self expression of the serum is of the order of one-' half an inch so that the maximum thickness of the clot to secure the best results should be at no point substantially greater than about an inch. As the clot contracts, the serum nearest the surface is first expressed with a resulting increase in density of the fibrin and blood corpuscles, until finally a 1 balance is set up between the contracting force of the] fibrin and the resistance op- I 1 p I rpos es, however, substantially complete self-Q1 h have been. greasedjmflordenthatjthe expression"offthefserum from" a clot; of normaljcozitractibility may be accomplished if:

12s. posedl'vto the flow o the Serum through the denser surface mass. For practical Pub the serum does not have to travel through the clot more than about one-half an inch.

The present invention provides a method of so forming the clot as to provide this desired short average path to the surface, and

' provided, as for instance, if the clot were left to stand in a shallow pan, at least one exterior surface of the clot would not only be in contact with the vessel, but would have to support the weight of the clot and consequently would not function as an exit surface for the serum. Thus, for the same percentage of yield the clot would have to be correspondingly diminished in thickness.- A

further advantage of the present -method,

which of commercial importance to expedite the expression of the serum as much as possible, is that the serum expresse from the clot is removed from contact therewith as soon as it is expressed, instead of being allowed to accumulate around the clot, thereby insuring "that there will be no back pressure on the clot to prevent the ready expres- ,sion and drainage of the serum.

As the yield ofblood from a given animal, such as a beef creature, is very large (the blood constitutes approximately 1/20th of the .animals weight) and'as the blood must be introduced into the container in which the clotting is to take place before the inception of coagulation, it is imperative that the operation be performed simply and expeditiously. On account of the short co-- agulation time, and the fact that an appreciable amount of time is required to drain the blood from the animal, it is as a practical matter necessary to catch the blood directly' from the animal in the container in which the 010 ting is to take place. Hence the container rust be of such shape and design as to be readily manipulated uponand as readily removed .from the slaughterhouse floor. It must be of'such form that the resulting clot shall have a high specific surface, that is a. high ratio of surface as compared to its mass, and during and afterthe expression of the serum it must be possible to remove the clot from the coagulating vessel without the least danger of rupture. That is, the clot must be removed as a whole and provision should be made, as already ex-- plained, for lifting the. clot after its formation in the vessel, to facilitate and expedite the expression and draining of the serum.-

Obviously various forms of apparatus for accomplishing the objects above set forth may be employed, but I have, by way of illustration, shown in the accompanying drawings one form of. apparatus suitable for carrying out the method.

Referring to the drawings,

Fig. 1 is a plan view of the apparatus partly broken away to show at the upper left-hand corner a plan and section on the plane of line 1-1, Fig. 3, and at the lower left-hand corner a plan and section on line 15, 1*, Fig. 3;

Fig. 2 is azsectional view on line 2-2 of Fig. 1;

Fig. 3 is a view partly in side elevation and partly in section on line -33 of Fig. 1;

Figs. at and 5 are enlarged details in section of the device for lifting the core and clot; and

Fig. 6 is a detail in side elevation of the end of the pipe through which the container is filled. 1

The form of container herein shown is open at the top and comprises the outer side walls 7 and bottom wall 8. convoluted or re-entrant inner walls 9 form a number of vertically disposed compartments 10 about an inch wide and similarly arranged at each side of a common central passage 11 (Fig. 1) which is also about an inch wide. Each compartment 10 and also the central passage 11 tapers or narrows toward the bottom to permit the clot to be more easily and freely lifted out of contact with the walls, .and all compartments open directly into the common passage 11. Thus theinterior of the oontainer'in which the clotis formed contains a number of re-entrant walls forming a chamber in which every point is distant from a wall within the limits of substantially complete or maximum self=expression of the serum.

A supporting core is arranged in the container comprising a top sheet 12 of wire screening or similar mesh and depending.

sheets 13 of similar screening extending downward through the centers of the several compartments 10. A depending central sheet 14, also of screening, extends down into the middle of passage 11 (Fig. 1). The entire composite core structure thus formed is carried by a central post 15, the lower end of which constitutes a valve controlling the outlet spout 16 at the bottom of the container. This spout also is provided with a cock 17. At the top of the post 15 is a loop handle 18 by which the core as a' whole may be lifted.-

In order to position the core properly within the container and hold it at all points out of contact with the container walls, guiding members are provided at diametrically opposite corners comprising a slotted bracket 19 fixed to the top screen 12 and making sliding engagement with the tongue 2O of a fixturesecured to a corner of the container. This fixture has a shoulder 21 which acts as a stop for the bracket 19 in its lowermost position.

The coverof the container is removable I and has an outer w-all 22 and an inner wall 23. The outer wall has 2. rolled under edge 24 restin 6n the top of the container walls 7 and a epending protective flange or skirt 25. A central inlet pipe or duct 26 extends through both walls 22 and 23. The pipe 26 has an inclined to 27. A removable cap 28 fits over the end of pipe 26 and has an inclined surface or cam 29 which raises and lowers the cap on the pipe 26 when the cap is rotated. Fixed to the cap 28 is a stem 30 which carries a projection or key 31 at its lower end adapted to pass through a key-hole slot 32 in the handle 18 of the core when the cap is in its lowermost position. When the cap is rotated a part turn, the key 31 will turn out of register with the slot 32 and as the cam 29; lifts the cap, the latter, acting'through the stem 30 and handle 18, will lift the wire mesh core.

The use of the apparatus in performing my process is as follows:

The entire inner walls of the container are greased as by a coating of paraffin. The parts are then assembled as shown in Figs. 1,. 2 and} 3 with the core in position Within the container, the cover closed, and the cock 1? closed. The delivery end 33, Fig. 6, of a pipe 34 which is directly connected to the animal being bled, at the time of slaughter, by one of the forms of special.

trocar described in separate applications heretofore filed 'by me, is .attached to the inlet pipe 26 and firmly held thereon by the bayonet joint consisting of slot 35 and pin 36. As the bleeding proceeds, the blood fiow's, wholly under cover, and so protected from contamination and dripping or spattering water, directly from the interior of the animal to the interior of the container until the latter isfilled to a level above As the blood is war in, any water vapor which might tend to condense and form on. the. under, side of the cover 22, which is in contact with the cooler outer air, will either fiowdown the underside of the cover 22.

.or drip on to the inner cover 23 and flow down the surface ofeither one or the other of said covers into the trough formed by the roller under edge,24. whence it will .drip through holes 38 (Fig.- 3), outside of the container, thus preventing access of water to the clot and consequent haemolysis, as already explained. The holes 38 and also the holes 37 perform the further office of per- I mitting air to escape as it is displacedby the infiowing blood.

In the presence of fibrin ferment, more or less uniformly distributed over the wire mesh core, 'coa ulation "begins almost immediately, an in a very few minutes a clot is formed about and through the wire mesh core with re-entrant surfaces conforming in shape to the shape of the interior walls of Thus a clot is produced of the container. large specific surface as compared to its mass, all points within the clot being distant fromthe surface within the limits of approximately the maximum self expression of the serum.

After the clot is completely 'formed and has begun to contract, the cap 28 is given a half turn causing the cam surface 29 to ride up on the cam surface 27, thereby lifting the core a short distance guided by the sliding connections 19' and 20, and drawing the clot as a whole out of contact with the converging walls of the container. The greased walls of the container will prevent the clot fromadhering and being ruptured.

The clot is supported by the core in this slightly raised position, uncut and unruptured, until the serum is expressed by the gradual'contraction of the clot. The entire surface of the clot being held out of contact with the walls of the container constitutes an effective exit surface through which the serum may be expressed. The serum will come off unstained by the blood corpuscles or haemoglobin, since the red blood corpuscles are not ruptured and are enmeshed and held by the fibrous network of the clot.

The raising of the core will lift the valve formed at the lower end of post 15 from its seat on the delivery spout. During the expression of the serum it is possible to leavetthe cock 17 of the outlet spout 16 closed, in which case the expressed serum will be held in the container around. the clot as the latter contracts and expresses the serum. However, in order to secure the maximum yield and to hasten the expressionof the serum-, th'e cock; 17 may be opened so as to drain off the serum into a suitable receiver as fast as it is expressed. This prevents any back pressure caused by the serum surrounding or contacting with the clot which tends to retard the expression of the serum from the clot and ultimately to balance and offset the capacity. of the clot to contract further, before the maximum degree .of self expression of the serum is achieved.

I claim 1. The art of obtaining serum from blood which comprises forming a blood clot with predetermined reentrant surfaces, holding the clot out of contact with the walls of the container whereby substantially its entire surface is an effective exit surface through which the serum may be expressed, and perniitting the serum to be expressed from the c 0t.

2. The art of obtaining serum from blood which comprises forming on a supporting core a blood clot with re-entrant surfaces, and permitting the'serum to be expressed from the clot.

3. The art of obtaining serum from blood which comprises forming on a supporting core a blood clot with re-entrant surfaces, supporting the clot on the core out of contact with the walls of the container whereby substantially its entire surface is an effective exit surface through which the serum may be expressed, and permitting the serum to be expressed from the clot.

from blood 4. The art of obtaining serum which comprises forming on a supporting core a blood clot with reentrant surfaces, supporting the clot on the core. out of contact with the walls of the container whereby substantially its entire surface is an effective exit surface through which the serum may be expressed, permitting the serum to be expressed from the clot, and removing the serum from contact with the clot as it is expressed to prevent back pressure thereof against the clot.

5. The art of obtaining serum from blood which comprises forming a blood clot with predetermined re-entrant surfaces in a closed container, preventing access of-water to the clot, and permitting the serum to be expresscd from the clot.

6. The art of obtaining serumfrom blood which comprises forming on a supporting core a blood clot with re-entrant surfaces in a closed container with unctuous walls, and

permitting the serum to be expressed from the clot. I

7 The art of obtaining serum from blood which comprises forming on a supporting core a blood clot with re-entrant surfaces in a closed container with unctuous walls, supporting the clot on the core in the container out of contact with the walls thereof, and permitting the serum to be expressed from the clot.

8. The art of obtaining serum from blood which comprises forming on a supporting core a blood clot with re-entrant surfaces in a closed container with unctuous walls, supporting the clot on the core in the container out of contact with the walls thereof, permitting the serum to be expressed from the clot, and removing the serum from the container as it is expressed to prevent back pressure thereof against the clot.

9. The art of obtaining serum frpm blood which comprises forming on a supporting core'a blood clot with reentrant surfaces in a closed container with unctuous walls, sup-- porting the clot on the core in the container out of contact with the walls thereof, permitting the serum to be expressed from the clot, and preventing access of water to the 0 0t.

10. The art of obtaining serum from blood which comprises forming on a supporting core in a closed container with unctuous walls a blood clot with re-entrant surfaces to produce a clot of large specific surface as compared to its mass, preventing access of water to the clot, supporting the clot on the core in the container out of contact with the walls thereof, permitting the serum to be expressed from the clot, and removing the serum from the container as it is expressed.

11. The art of obtaining serum from blood, which comprises forming a blood clot on a supporting core in the presence of a fibrin ferment, and permitting the serum to be expressed from the clot.

12. The art of obtaining serum from blood, which comprises forming a blood clot on a supporting core in the presence of a fibrin ferment in a closed container having unctuous walls, and ermitting the serum to be expressed from t e clot;

13. The art of obtaining serum from blood, which comprises forming a blood clot with re-e'ntrant surfaces on a supporting core in the presence of a fibrin ferment in a closed container having unctuous walls, and permitting the serum to be expressed from the clot.

14. The art of obtaining serum from blood, which comprises forming a blood clot on a supporting core in the presence of fibrin ferment shreds, and permitting the serum to be expressed from the clot.

15. The art of obtaining serum from blood, which comprises forming a blood clot with re-entrant surfaces on a supporting core in the presence of fibrin ferment shreds tially its entire surface is an effective exit surface through which the serum may be expressed. r

17. The art ofobtaining serum from blood which comprises forming a blood clot of large specific surface as compared to its mass, all points within the clot being distant from the surface within the limits of substantially maximum self expression of the serum, holding the uncut and unruptured clot out of contact with the walls of the container whereb substantially its entire surface is an e ective exit surface through which the: serum maybe expressed, and removing the serum from contact "with the clot as it is expressed to prevent back pressure thereof against the clot.

18. The art of obtaining serum from blood which comprises forming on a supporting throu h which the serum may be expressed.

19. he art of obtaining serum from blood which comprises forming on a supporting core in a'cont'ainer havin unctuous walls a 7 blood clot of large speci 0 surface as compared to its mass,-all points within the clot being distant from the surface within the limits of substantially maximum self expression of the serum, and holding the clot out of contact with the walls of the container whereby substantially its entire surface is an effective exit surface through which the serum may be expressed.

20. The art of obtaining serum from blood which comprises forming a blood clot in a container having upwardly flaring walls,

- thereby producing a downwardly tapered clot, lifting the tapered clot to break contact with the flared walls, and suspending the clot, lifting the-tapered clot to break contact with the flared walls, suspending the clot substantially out of contact with the walls to permit the expressfoniof the serum throughout substantially the entire surface of the clot, and draining off the serum as it ii expressed to avoid back pressure on the 0 0t. A 1

22. The art of obtaining serum from blood which comprises forming a blood clot in a c tainer having upwardly flaring walls, thereby roducing a downwardly tapered clot, l ftlng the tapered clot to break contact with the flared walls, suspending the clot substantially out of contact with the walls to permit the expression of the serum throughout substantia y the entire surface of the clot, and opening an outlet in the bottom oftthe oontalner to drain off the serum,

the outlet being closed at its month during a the formation of the clot to prevent blood clotting therein. l

Signed by me at vBoston, Massachusetts,

this 1411a of Janna; 1920. WIIEEJIAM B TON WESCOTT. 

